1. Field of the Invention
The present invention relates to a photonic system that compresses and decompresses data.
2. Description of Related Art
Electronic systems process and transfer information that is defined by binary bit strings. For Example, under the American Standards Committee Information Interchange (ASCII) code the letter "a" is defined by the binary bit string "10000001". Binary bit strings are used to define information because electronic devices operate with transistors which have one of two states, high or low.
Binary information is typically stored within a storage device in a serial format. For example, hard disk drives contain a magnetic head which magnetizes or senses the magnetic field of a rotating magnetic disk. Each magnetized area represents a single bit of data. To write data, the head will magnetize areas of the rotating disk in accordance with a series of clock signals. Each clock signal corresponds to a time period required to store a single bit. Therefore it typically takes 8 clock cycles to write an 8 bit string. Optical disk drives operate in a similar manner, wherein a light beam is directed toward a rotating disk which has areas that are either reflective or non-reflective. A reflective area may represent a binary 1 and a non-reflective area may represent a binary 0, or visa versa. The light beam is then detected by a detector and converted into corresponding digital electrical signals. The detectors convert the light energy into electrical signals in accordance with a series of clock signals.
Electronic information is transmitted between two or more devices in accordance with a predetermined protocol. For example, digital information is commonly transmitted between electronic devices separated by large distances using facsimile (FAX) or (MODEM) protocols. Computers linked together within a network typically transmit data using a conventional network protocol such as Ethernet. Present conventional transmission protocols require a serial transfer of information between serial ports of the devices. Like the heads of a disk drive, the serial ports of electronic devices transmit and receive each bit of information in accordance with a clock signal. Generally speaking, it requires at least 8 clock signals to transfer 8 bits of information.
To reduce the transmission time of transferring data, various data compression techniques have been employed. Present data compression methods typically reduce the size of the bit string to a smaller number of bits which can then be decoded back to the original bit string. Examples of conventional transmission data compression techniques include run length encoding, Huffman coding and quadrature amplitude modulation.
There are also data compression methods for storing information. For example, U.S. Pat. No. 5,003,307 issued to Whiting et al. discloses a method for compressing data that is stored on a hard disk, thereby increasing the data capacity of the disk drive. Although these methods are effective in compressing data, present data compression techniques all require electronic devices to perform the various steps of compression. Electronic devices consume power which can be critical to small systems such as a laptop computer. The operation of steps needed to compress the data may require a relatively large number of clock cycles which may increase the time to transfer or store the data. Additionally, some data compression techniques such as quadrature amplitude modulation have limited compression ratios.
Optical based systems such as fiber optic networks are used when high speed transmission is desired. Likewise, optical storage devices are becoming increasingly popular because of the durability of the disk. To date, data compression techniques used in optical systems still require electronic devices in compress and decompress the data. It would be desirable to have an optical data compression system and method, that is faster, consumes less power and can provide higher compression ratios than compression techniques in the prior art.